Swiveling tool support for earthworking machine



June 4, 1968 v A. B. TOMLINSON 3,386,295

SWIVELING TOOL SUPPORT FOR EARTH-WORKING MACHINE Filed July 22, 1966' aSheets-Sheet 1 INVENTOR. 400/5 5. 727/144 MASON,

BY v mau wm ,M/HIJ/XL 4 T TOE/YE Y5.

United States Patent Ofice 3,385,295 Patented June 4, 1968 3,386,295SWIVELING TGGL SUPIQRT FOR EARTH- WORKING MAITHINE Audie B. Tomlinson,PD. Box 864, Rufus, Oreg. 97650 Filed July 22, 1966, Ser. No. 567,094Claims. (Cl. 74-63) This invention relates to a swiveling tool supportfor an earth-working machine and, work particularly, to a support, for ahoe, bucket, shovel, or other tool, capable of rotating completelythrough 360 degrees so that it may be positively braked to hold the toolat any desired angle in a horizontal plane with respect to the verticalaxis of the support, the support being capable of installation on a boomso as to swing in the plane of the boom and the boom being rotatable andswingable on the earth-working machine.

Conventional earth-working machines for excavating pits, diggingtrenches and the like are normally provided with a boom which isliftable and lowerable in its own plane and swingable about a verticalaxis out of said plane, the digging hoe, or bucket, being mounted on theend of the boom for pivotal movements in the plane of the boom to outerdigging and lifting positions and inner lowering and emptying, orfolded, positions. Such conventional machines are restricted in theirapplication because the digging and emptying movements of the toolcutting, or digging, edges are confined to the plane of the boom. Whenconventional machines are provided with tool holding supports capable ofturning the tool, they are usually subject to the followingdisadvantages. The mounting is such that the maximum angle of rotationis less than 360 degrees. When the tool is turned to a desired angularposition, the braking means provided will not positively lock and holdthe tool fixed in said position under heavy load. For example, if thebraking means is actuated by fluid pressure, a heavy load on the toolwill exert differential pressures on opposite sides of the piston of thefluid pressure device allowing leakage of the pressure fluid topartially or fully release the brake. If the braking means isconstituted by pawls meshing with teeth, the tool can only be locked incertain angular positions conforming to the meshing positions of thepawls and mating teeth. If the braking means are controlled by cablesthese stretch with load and prevent positive looking. A furtherdisadvantage of conventional tool supports is that their pivotalmounting structures for swinging the tool in the plane of the boom andfor folding the tool toward and away from the boom are such that theyfail due to clogging by dirt and debris, or rusting, and in certainangular positions of the tool the mechanism for folding, or closing thetool toward the boom cannot operate.

It is a primary object of the present invention to provide a swivelingtool support for earth-working machines which will overcome theabove-stated disadvantages of conventional tool supports.

An important object of the invention is to provide a tool support forearth-working machines capable of swiveling the tool completely throughan angle of 360 degrees in either direction and about inclined axeslying in a vertical plane through the outer end of a boom on themachine.

Another object of the invention is to provide an improved tool support,of the above-described characteris tics, which can be braked, orpositively locked, in a desired position once it has been turned througha requisite angle.

It is a further object of the invention to provide a tool support, ofthe above-described characteristics, mounted in a sealed enclosinghousing which enables complete and continuous lubrication of thebearings and drive parts of the rotating support and protects said partsfrom contamination by slush, dirt, rust, etc.

Yet another object of the invention is to provide an improved toolsupport, of the above-described characteristics, in which the means forswinging the support with respect to the boom and for swinging theshovel, or tool, with respect to the support are so mounted as tominimize contamination by dirt, slush and the like and geometricallyarranged to permit operation in any angular position of the tool andduring rotation of the tool support.

A still further object of the invention is to provide a tool support,having the above-described characteristics, and in which drive means isprovided for positively rotating the tool support, said means having agear reduction train including a worm, the worm serving to positivelybrake and lock the tool in any desired angular position when the Wormdrive is stopped.

Still another object of the invention is to provide a swiveling toolsupport in which the drive is omitted, turning of the tool beingeffected by weight of the tool and/ or swinging of the boom of theearth-working machine on which the tool support is installed, but inwhich, nevertheless, positive braking means is provided under control ofthe machine operator to lock the tool support in any desired angularposition.

Yet a further object of the invention is to provide an improved toolsupport, having the above-described characteristics, which is of simpleconstruction, easy and inexpensive to fabricate, easy to install anduse, and relatively free of extensive maintenance.

The novel features that are considered characteristic of the inventionare set forth with particularity in the appended claims. The inventionitself, however, both as to its orgganization and its method ofoperation, together with additional objects and advantages thereof, willbest be understood from the following description of specificembodiments when read in connection with the accompanying drawings,wherein like reference characters indicate like parts throughout theseveral figures and in which:

FIGURE 1 is a plan view of a portion of the boom of an earth-workingmachine equipped with a tool support according to the invention;

FIGURE 2 is a side elevation of the upper portion of the tool supportshown in FIGURE 1;

FIGURE 20 is a continuation of the view of FIGURE 2, showing the lowerportion of the support including the tool attached thereto;

FIGURE 3 is an enlarged sectional view taken on line 3-3 of FIGURE 2 andlooking in the direction of the arrows;

FIGURE 4 is a sectional view taken on line 4-4 of FIGURE 3, looking inthe direction of the arrows;

FIGURE 5 is a reduced elevational view similar to FIGURE 2, but of aslightly modified embodiment and showing the tool support in a differentposition in which the unshown tool is lifted slightly and swungoutwardly from the boom;

FIGURE 6 is a side elevation similar to FIGURE 2, but of anothermodified embodiment of the tool support;

FIGURE 7 is a sectional view taken on line 7-7 of FIGURE 6 and lookingin the direction of the arrows; and

FIGURE 8 is a fragmentary sectional View similar to FIGURE 3, butshowing still another embodiment of the invention. I

Referring now more particularly to the drawings, in FIGURES 15 are shownembodiments of the invention suitable for operating at low torques andfor application to heavy loads. In FIGURE 2a, a conventional diggingtool 19, such as a bucket, hoe or shovel, is shown attached by pivot 12to the lower end of a tool support shaft 14. A rear portion of the toolis pivoted at 16 to the lower end of piston rod 18 of a pressure fluid,power device 29, such as a double action hydraulic cylinder havingpressure fluid connections 22, 24 and whose upper end is pivoted at 26between a pair of brackets 25$ welded, or otherwise suitably secured, tothe support shaft 14. A pair of bent links 34 are pivoted at their endsabout pins 32, 34 to the shaft 14 and the rod 18 of the hydrauliccylinder respectively. Thus, application of pressure fluid to thecylinder through nipples, or connections, 21; or 2 2 will tilt the tool1% with respect to the support shaft 14 in one direction or the oppositeso as to assist movements of other parts either in digging or emptyingearth.

The upper end of support shaft 14 is rotatably supported in housing 36by means to be later explained, the housing being pivoted to swing inthe plane of the boom 38 when pressure fluid device 49, such as ahydraulic cylinder with ram 42 and connecting conduits 4-4, 46, isoperated. In the embodiment illustrated the housing 36 is of cylindricalshape, although other shapes are possible, and is provided withdiametrically opposed projecting stub axles 48 which are pivotallysecured in openings in the forks 50 at the end of the boom. A pair ofspaced brackets 52, attached to the boom, serve to hold pivot -1, whichalso passes through an opening in a projection 56 on the inner end ofcylinder 40. The outer end of the ram 42 of the fluid pressure cylinderis pivoted at 58 to a pair of spaced brackets 69 having arcuate legswelded to the upper end of housing 36. Thus, application of pressurefluid through conduits 44 and 46 in one direction or the other willextend, or retract, the ram 42 to swing housing 36 in the plane of theboom so as to fold the tool at the bottom of shaft 14 toward the boom,or away from the boom, respectively.

FIGURES 2 and 2a show the tool support with the pressure device 40actuated to approximately mid-position of ram 42 wherein the toolsupport shaft 14 is substantially vertical. FIGURE 5 illustrates aslightly modified form of the tool support with the pressure device 4%actuated so that ram 42 is somewhat withdrawn from the position ofFIGURE 2 and the shaft 14 and supported tool are swung outwardly fromthe boom.

The means for rotatably suporting and driving the tool support shaft 14are best shown in FIGURES 3 and 4. The cylindrical housing 36 is closedat its upper end by cap plate 62 having an opening 64 for passage ofpart of a gear train, and separated from the upper edge of the housingby annular shims 66 and the O-ring seal 68. The cap plate is secured bystuds 70 and nuts 72. The housing is closed at its bottom by plate 74secured by cap screws 76 with interposed shims 78. The bottom plate isprovided with a large opening 80 for passage of a reduced diameterportion 82 of shaft 14. The shoulder of shaft 14 adjacent portion 82also supports a ring seal 84 having a tongue extending between lips ofseal 86 seated in an annular recess in bottom plate 74. The interior ofhousing 36 is shouldered at 88, $1 to seat and support the conical outerraceways 92, 9 of bearing devices including cone bearing 94, @d andinner conical raceways )7, 98. The inner conical raceways cooperate withsaid bearings and frictionlessly support and engage reduced portions ofshaft 14. A third pair of conical raceways 100, 1&2 with associatedconical bearings 104 is disposed at the lower end of the housing andseated on the bottom plate 74. The upper end of shaft 14 has threads 106to receive a holding nut 163 which, when tightened to adjust raceway $7,is locked in place by the pin 11% in turn securely fastened by a snapmetal band 112 surrounding the nut.

As thus far described, the tool support shaft is supported by the nut1&8 through the bearings 94 and raceways 92, 97, from the shoulder 88 ofthe casing, and is free to rotate continuously through and beyond 360degrees in either direction. The bearings not only provide for rotationwith minimum friction but also operate to take thrust in both axialdirections of the shaft, upward thrust being exerted by the shouldersadjacent part 82 of shaft 14 against the bottom plate 74, and thebearing raceways 100, 58, bearings 104, and raceways 102, 94 to shoulder99 of housing 36.

To rotate the shaft, there is provided drive means now to be describedand including a spur gear 114 fixed to the upper end of a reducedportion of shaft 14, above threads 13 6, by splines 116 and the capplate 118. Shims 120 are placed between the cap plate and the uppersurface of the gear 114, the cap plate being securely fastened to theshaft by cap screws 122 and locking wire 124 passing through the headsof all the cap screws. A splined pinion 1.26 is secured to the bottomend of shaft 128 by holding screw 13%. The shaft passes through aperture64 of the cap plate 62 and through the bore of a neck portion 134 of agear reduction casing 136. A conventional motor 138 for rotating shaft14 through the gear reduction device is provided and may be of anysuitable type, as for example a fluid activated, rotary device, thepressure fluid being fed and returned through flexible conduits 140, 142partially shown in FIGURE l. However, should other sources of power thanhydraulic pressure, or compressed air, be more readily available on themachine in which the tool support is installed, obviously such otherpower may be used to rotate the tool support shaft. Thus, if electricpower is available, the motor 138 may be a reversible electric motor.

The motor drive shaft 144- carries a worm 146 which meshes with gear 14%fixed to the upper end of shaft 128 and within casing 136. Thus, worm 1-26, gear 148, pinion 126 nd spur gear 114 form a gear reduction trainuseful for converting the high speed and low torque of motor 138 to lowspeed and high torque more suitable for rotating the tool support shaft14 under heavy load. In this manner, high duty smooth operation isobtained.

A further feature of the described drive is that the 90 degree relationof the shafts of worm 146 and its meshing gear 148 and the resultinggeometric relation of their teeth positively prevent the weight of aheavy load on the tool from rotating the shaft 14 when the worm isundriven. At such time angular motion of the gear 148 is opposed by theteeth of worm 146 since the worm teeth can turn only about their ownaxis not parallel to the axis of gear 148. This will be clear fromobservation of the similar gear 148a and Worm 146a shown in FIG- URE 7,turning of the gear 148a in the plane of the paper tending to force theworm teeth in axial directions rather than to turn them about theiraxis. Thus, the Worm serves as a positive braking means for holding therotated support shaft 14 in any position to which the machine operatorhas driven the same by operation of the motor 138, it being merelynecessary to stop flow of pressure fluid to the motor to hold the shaftin the selected angular position.

Fro the above description of the heavy duty embodiment of FIGURES 1-4,it will be apparent that the machine operator may control the machine inthe conventional manner to turn, lift and lower the boom 38, swing thetool 10 toward and away from and in the plane of the boom by applicationof pressure fluid in the cylinder 4%, and tilt the tool It toward oraway from shaft 14 by applying pressure fluid in the appropriatedirection in cylinder 20. When it is necessary, or desirable, to rotatethe tool 16 out of the plane of the boom, the operator need merely applypressure fluid to motor 138, observing the amount of turn of the tool,and when the tool has reached the proper angle to then stop the flow ofpressure fluid to motor 138. This will stop the drive to the worm 146and the worm will hold and positively lock the shaft 14 from rotatingout of the angular position to which it has previously moved. Thevariations of angular direction of the tool are useful, for example, in

digging a trench in a slopping hillside, the machine remainingstationary above or below the trench. When it becomes necessary tochange the angle of the tool somewhat in order to, for example, engagein a wedging direction under a heavy boulder, or the like, to lift anddeposit it, such changes in the rotational angle of the tool are easilymade by applying pressure fluid to motor 138 using valve controls in thecab of the machine.

The tool closing cylinder 20 and cylinder 40 for tilting housing 36,both being mounted at the upper end and upper side of the boom, arerelatively removed from earth debris, slush, and the like, being dug bythe tool carried at the bottom of shaft 14. Cylinder 20 being directlyaffixed to the rotating shaft is thereby enabled to tilt, or close, thetool in any angle of rotation of the shaft.

It will be noted that the bearings and gears enclosed in housing 36 andcasing 136 also are free from contact with slush, debris and othercontaminating matter, suitable seals being employed at all openings inaccordance with good engineering practice to retain the lubricant insideand dirt outside. The bearings and the gears are thus sealed from theatmosphere and operate in lubricating grease periodically applied underhigh pressure through the zerk fitting 150. Such lubricant fills theentire housing 36, covers the bearings and gears therein and enters theworm gear casing 136 through opening 64 in the cover 62 and through thebore of the casing neck portion 134. Thus, both the bearing means andthe reduction gear drive for the shaft are constantly maintained willlubricated through a single fitting. A lubricant relief plug 152 isthreaded in an opening in the upper surface of casing 136 for expellinggrease when the interior of the gear casing is filled.

The lower bearings surrounding shaft 14 may be adjusted after wear byremoval of the bottom plate 74 to subtract or add shims 78. Adjustmentof the upper bearings is possible upon removal of top plate 62 andturning of the holding nut 108. In the initial adjustment of thebearings, shims are added of subtracted to achieve the desired thrustwithout play.

The modification illustrated in FIGURE 5 is in all respects identicalwith that of FIGURES 1-4 except that stub axles, or trunnions 48 areomitted and a pair of brackets 132 having semicylindrical portions arewelded to the housing 36. The boom 38 is secured between said bracketson pivot 133.

In FIGURES 6 and 7, there is shown a modified embodiment of the toolsupport adapted for use with lighter loads. In this embodiment, the toolsupport is constructed and operates essentially the same in allrespects, as described for the embodiments of FIGUR ES 1-5, except asindicated below. The gears 114, 126 and 148 are omitted and a largediameter gear 148a which directly meshes with the worm 144a issubstituted for gear 114 on the upper end of shaft 14. An opening 154 isformed near the upper edge of the wall of housing 36a to communicatewith the interior of a cylindrical housing extension 156 for enclosingworm 146a and disposed tangent to cylinder 36a. The gear and worm meshin opening 154. Extension 156 may be cast integral with housing 36 orformed separately and attached thereto. The cylinder 156 is closed by anend plate 158 secured by cap screws 160. The worm shaft 144a is receivedin a bearing socket in plate 158 and thrust is taken by spacer sleeve162 and thrust bearings 164. The opposite end of the worm shaft 144a issplined at 166 to a coupling 168 fixed to the end of the drive shaft ofthe motor 138a. The motor closure plate 170 is secured to an annularflange 172, which in turn is secured to one end of extension cylinder156 by any suitable means, such as screws 173. Another spacer sleeve 174and thrust bearings 176 are retained at the adjacent end of worm shaft1440 by an abutment collar on flange 172.

It will be apparent that the modification illustrated in FIGURES 6 and 7will operate in all respects like that described for the heavy dutyembodiments of FIGURES l-S, the omission of certain gears from the speedreduction device changing the speed reduction obtained, but the Worm146a still being effective, because of its right angled disposition tothe gear 148a, to exercise braking friction and locking that willprevent rotation of the tool support shaft 14 under lighter loads.

In FIGURE 8 is illustrated still another embodiment of the inventionwhich is in all respects similar in structure and mode of operation tothat described and illustrated in FIGURES 1-5, except that gear 114 andpinion 126 are omitted, as are all positive means for rotating theshaft, and a brake drum 178 is substituted for gear 114. Brake shoes 180are positioned for engagement with the brake drum upon application ofany suitable power means such as the fluid pressure rams 182 undercontrol of the operator in the cab of the machine. To rotate the toolsupport shaft 14 of the FIGURE 8 embodiment through any desired angle,there being no positive drive means, the operator must depend on theweight of the tool and/or the swinging of the boom and tilting of thehousing 36. With experience obtained by trial, a skillful operator maycontrol the boom 38, the shaft housing 36, tilt cylinder 40 and the toolclosing cylinder 20 in various degree and combination to cause swingingmovements such that the weight of the tool will rotate the shaft 14 intoa desired angular position out of the plane of the boom, at whichinstant the operator will apply pressure fluid to engage the brake shoes180 and clamp the brake drum 178 fixed to the shaft 14, thereby fixingthe tool at the desired angle. Should it become necessary to change thisangle, similar manipulations of the boom, the shaft housing, and thetool will enable relative rotation of the tool with respect to thehousing until the tool is properly oriented. In this embodiment of theinvention the structure is simplified and less costly to fabricate andinstall, although a little more difficult to operate and use.

Although certain specific embodiments of the invention have been shownand described, it is obvious than many modifications thereof arepossible. The invention, therefore, is not to be restr zted exceptinsofar as is necessitated by the prior art and by the spirit of theappended claims.

What is claimed is:

1. A swiveling tool support for attachment to the boom of anearth-working machine, comprising a housing, means for pivotallyattaching said housing for swinging movement in the plane of a boom, atool support shaft having an upper end disposed in said housing and alower portion protruding therefrom, bearing means supporting said shaftfor rotation about its own axis through an angle of 360 degrees, brakingmeans to retain said shaft locked against rotation, and means on thelower portion of said shaft for pivotally supporting an earth-workingtool.

2. A swiveling tool support according to claim 1, wherein said brakingmeans comprises a drive worm and a coacting gear connected to said toolsupport shaft, whereby the worm acts as a brake when the Worm is notdriven.

3. A swiveling tool support according to claim 1, wherein said brakingmeans comprises a drum secured to the upper end of said tool support,shaft brake shoe means for engaging said drum, and power actuating meansfor moving said shoe means into and out of engagement with said drum.

4. A swiveling tool support according to claim 2, wherein is furtherprovided means for rotatably driving said shaft comprising a gearreduction mechanism including said worm.

5. A swiveling tool support according to claim 4, wherein said gearmechanism for driving the shaft comprises a motor having a drive shaftcoupled to said worm.

6. A swiveling tool support according to claim 5, wherein said worm anda portion of a speed reducing gear train forming said gear reductionmechanism are enclosed in a casing disposed outside said housing andsecured thereto, said casing having a neck portion whose borecommunicates with said housing through an opening in the latter forpassage of a shaft of said gear train.

7. A swiveling tool support according to claim 6, wherein said housingis provided with a lubricant receiving fitting for injecting lubricantto the tool support shaft and said bearing means, said fitting servingalso to lubricate said worm and portion of the speed reducing gear trainin the casing by passage through said opening of the housing and bore ofthe neck portion of the casing.

8. A swiveling tool support according to claim '7, wherein said speedreducing gear train includes a pinion fixed to the lower end of saidgear train shaft, and a mating gear within said housing fixed to theupper end of the tool support shaft.

9. A swiveling tool support according to claim 1, wherein said bearingmeans include cone-shaped bearings and races arranged to withstandthrust in the axial directions of said tool support shaft.

References Cited UNITED STATES PATENTS 3,027,026 3/1962 COuquet 37-1033,042,234 7/1962 Davis 214-141 3,069,033 12/1962 Ferwerda 2141413,135,403 6/1964 Przybylski et al. i 214 141 3,224,608 12/1965 Yadon eta1. 214141 3,319,803 5/1967 Northcott 214-141 FRED C. MATTERN, JR,Primary Examiner.

W. S. RATLIFF, Assistant Examiner.

1. A SWIVELING TOOL SUPPORT FOR ATTACHMENT TO THE BOOM OF ANEARTH-WORKING MACHINE, COMPRISING A HOUSING, MEANS FOR PIVOTALLYATTACHING SAID HOUSING FOR SWINGING MOVEMENT IN THE PLANE OF A BOOM, ATOOL SUPPORT SHAFT HAVING AN UPPER END DISPOSED IN SAID HOUSING AND ALOWER PORTION PROTRUDING THEREFROM, BEARING MEANS SUPPORTING SAID SHAFTFOR ROTATION ABOUT ITS OWN AXIS THROUGH AN ANGLE OF 360 DEGREES, BRAKINGMEANS TO RETAIN SAID SHAFT LOCKED AGAINST ROTATION, AND MEANS ON THELOWER PORTION